#include <arpa/inet.h>
#include <cstring>
#include <iostream>
#include <netinet/in.h>
#include <sys/socket.h>
#include <unistd.h>

#define PORT 8080

int main()
{
    int server_fd, new_socket;
    struct sockaddr_in address;
    int opt = 1;
    int addrlen = sizeof(address);
    char buffer[1024] = { 0 };
    std::string hello = "world";

    // 创建 socket 文件描述符
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }

    // 绑定 socket 到 localhost 的 8080 端口
    if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {
        perror("setsockopt");
        exit(EXIT_FAILURE);
    }
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(PORT);

    if (bind(server_fd, (struct sockaddr*)&address, sizeof(address)) < 0) {
        perror("bind failed");
        exit(EXIT_FAILURE);
    }

    // 监听
    if (listen(server_fd, 3) < 0) {
        perror("listen");
        exit(EXIT_FAILURE);
    }

    // 接受连接
    if ((new_socket = accept(server_fd, (struct sockaddr*)&address, (socklen_t*)&addrlen)) < 0) {
        perror("accept");
        exit(EXIT_FAILURE);
    }

    // 读取数据
    read(new_socket, buffer, 1024);
    std::cout << buffer << std::endl;

    // 发送数据
    send(new_socket, hello.data(), hello.length(), 0);

    // 关闭 socket
    close(server_fd);
    return 0;
}
